Even though I enjoy watching porn and looking at naked women myself (and I'm a straight female), I absolutely cannot emotionally cope with my boyfriend looking at girls in swimsuits let alone naked and especially in porn. What's wrong with me?

If you are not confident in yourself and your relationship then you see this as an afront to yourself. You need to figure out where the root of the problem is. Have you had this problem before with other boyfriends? On one hand your seem to say your not a prude and on the other you appear extremely jealous. You alone need to figure out which one is driving your current emotions so you can get help sorting them out.

I have always been like this. I have always felt so embarrassed about my own body. My boyfriend makes me feel loved and sexy. I know he loves me just how I am. I've tried to desensitize myself by looking but it makes me even more aware of all the possibilities he could be looking at. I know I'm not rational over this but don't seem to be able to help myself.
If I see a naked or even semi naked woman on TV for example, I'll enjoy it unless he's watching too. If he's watching, I go red and feel hot and insanely jealous. Crazy?

Not crazy, but so insecure that you might want to see a therapist for a while.
I can appreciate your feelings about your own body, because I have always felt the same way. (I try to make jokes to hide feelings. I think that's an acceptable solution. We can't all afford years of analysis.)
In other words, IF you don't want to lose your boyfriend, it is in your interest to FORCE yourself to curb your jealousy. Tell yourself you can stop, work on it, make it a course called Curbing Jealousy 101, get him involved, have him shout out a nonsense keyword when it starts happening, and give yourself a final exam in 3 months.

Many women feel insure, and it is something you will need to deal with, if you require counseling, get it, since it can effect long term relatinships

Confidence of the outer self usually starts with the inner self. Haven't you ever seen people and you think "how could they wear that????".

Its because they may not care what you think rather they just care about what makes them feel good. That is the starting point for you. To start feeling good about yourself. One way that may work is to start being grateful for what you do have and see around you. Since you have had this problem before then I have to take the leap for it to mean with other boyfriends.

Do you realize how many out there are so painfully she they can't even get that far? So since your not one of them its something to be grateful for. We all are our own worst critic. So just stop with that. Be grateful for who you are and take power in yourself. Celebrate who you are every day by displaying the confident person you can be. If you still think you look bad then go to a nudist website and take a look at what is walking around the beachs. They may not be pretty but their confidence is beaming. Its your choice to remain as you are or not. But since your reaching out then maybe its time for a change.